Valved mixing container or package



Nov. 1, 1966 A. P. com-:LLA ET AL 3,282,412

VALVED MIXING CONTAINER OR PACKAGE 2 Sheets-Sheet l Amy Filed Nov. 6, 1963 Nov. 1, 1966 A. P. coRELLA ET AL 3,282,412

VALVED MIXING CONTAINER OR PACKAGE 2 SheetS-Sheet 2 Filed Nov. 6, 1965 United States Patent O 3,282,412 VALVED MIXING CONTAINER OR PACKAGE Arthur l. Corella, North Hollywood, and William S. Schneider, Glendale, Calif., assignors of ten percent to Wayne V. Rodgers, South Pasadena, Calif.

Filed Nov. 6, 1963, Ser. No. 321,958 18 Claims. (Cl. 206-47) The present invention relates Igenerally to containers and packages having flexible walls. It is more particularly concerned with an improved type of such package which may be used as a container for the purpose of merchandising a product to which the user will later add a liquid and will then mix the :added liquid and the product together by exing'the walls of the bag, the container being provided with a one-way valve through which the liquid may be introduced into the package by the user.

Many different types of products are now sold in a dry form and are to be mixed by the user with a liquid, such as water, as a step in the subsequent processing or use of the original material. Examples of such products requiring the addition thereto of a liquid for further processing include cake mixes, pie crust mixes, pancake mixes and other food products which are sold in dry form and are to be mixe-d with milk or water by the user. Other examples of similar requirements may be found among various non-food products such as plaster of Paris, cement mixes, and various liquid plastics to which a liquid catalyst is to be added.

On well-known manner of using products of this character involves emptying the contents of the package in dry form into a suitable mixing container, adding the desired liquid in the proper amount, and stirring or agitating the liquid and the dry mix together with a suitable implement. As a convenience to the user, such products are preferably sold in packages having flexible walls and into which the proper amount of added liquid may be placed, the liquid and the dry product being mixed in the package by flexing or kneading the walls of the package to obtain the desired mixing action. After the desired mix-ture is secured, it is then ejected from the package through an opening in the package wall which is formed for that purpose. M-any advantages accrue to the user from a package of this type, particularly the saving in time and trouble of cleaning up a second vessel in which the mixture would otherwise be prepa-red since the original package constitutes a disposable mixing container.

One known type of container for this service is a sack-like container open at one end; but this has several objections. It is diflicult to close. If one hand is employed to hold the originally open end closed, only one hand is free to do the mixing. When the mixing is completed, the mixed contents are discharged through the open end; but the opening is so large that it is impossible for many users to discharge the content-s at a relatively slow, controlled rate. These objections can be overcome by a valved opening through which materials may be placed in the bag and by discharging them later through a second opening of a size to permit controlled discharge.

Prior designs of packages of this type with varied inlet passages have not been entirely successful, for

3,282,412 Patented Nov. l., 1966 ice various reasons. The chief problem has been to provide a one-way valve which remains securely closed `during the mixing operation. In knonw designs of packages, the valve does not always remain securely closed, with the result that some of the contents escapes through the partially open valve. Sometimes it appears as if the spreading apart or other relative movement of the outer walls of the package during the mixing operation causes separation `of the elements of the valve, thus opening an escape passage for contents of the package. In other designs it is possible for a fold to appear in one of the walls of the valve structure, the fold forming an exit path for the package contents. In any event, once even a small amount of the contents of the package enters the valve structure, the presence of this material tends to hold open the valve and make escape of further material a relatively simple matter.

Thus, it is a general object of the present invention to provide a novel design of a package of this general type containing a valve through which liquid may be int-roduced into the product-holding space within the package and the product therein and the liquid mixed together by kneading -or flexing of the outer walls of the package without causing the valve to open and allow the escape of any of the contents during the mixing operation.

Another object of the invention is to provide in a package of this general type a one-way valve structure through which water or other liquid or dry pow-ders and the like, as required, may be easily introduced into the package.

Another object of the invention is to provide a package of this general type containing a one-way val've structure in which the walls forming the passage for introducing a substance into the package remain in contact at all times after introducing the substance, thus forming a one-way valve which is reliable in operation but simple in construction.

A further object is to provide a package of this general type containing a one-way valve structure, such that the package can be hermetically sealed to safeguard the contents against loss of mixture or contamination by the entry of foreign matter and yet is of such character that the hermetic seal can be broken easily by the user to open the inlet passage while leading the valve structure intact.

Still another object of the present invention is to design a package of this character which can be easily manufactured on high speed, automatic machinery of the formand-iill variety, thus making the package relatively inexpensive and readily available in large quantities, a characteristic essential to a commercially worthwhile package.

These objects of the invention have been attained by providing a package containing a lirst product to which a substance, typically `a liquid, is to `be added, comprising a pair of opposed ilexible outer walls joined together to form an interior product-receiving space in which there is a quantity of the product; and a pair of opposed flexible inner walls that are disposed between the two outer walls and are joined together at space-d apart areas extending across the inner walls from a position adjacent a lirst edge thereof to a position adjacent the opposite edge thereof in order to define a filling passage between said inner walls, the inner walls each being attached to the respective adjoining outer wall near the inlet end of the passage adjacent said first edge of the inner walls, and said inner walls being attached to each other and both being attached to one outer wall at each side of the exit end of the passage. The points of attachment of the two inner walls to said one outer wall are at positions such that there is a small amount of slack left in the portions of the two inne-r walls forming the exit end of the filling passage when the outer wall to which the inner walls are attached is stretched taut. This condition creates an arched configuration of the two inner walls which holds them in contact with each other and resists any tendency of the product being mixed in the package to enter between the inner walls and separate them.

The two outer walls of the package are joined together at the margin of the package at the inlet end of the liquid passage to provide a part of means that hermetically seals the package. The marginal joint may take various forms but it extends entirely across the package and is spaced from and is generally parallel to seals that join each of the inner walls to an adjoining outer wall. Thus, the hermetic seal of the package can be broken by cutting across the package between the marginal joint and the last mentioned seals; thereby opening the package and exposing the inlet end of the liquid passage for addition of liquid to the package.

Reference has been made so far chiefly to embodiment of the invention in a package; but it will be understood from later description how the invention also comprehends a container to which two or more different substances, to be mixed together, may be added in succession through the same lling passage. The contents are then mixed as described. In either the container or the package the contents are discharged through a second opening in the outer walls.

How the above objects and advantages of the present invention, as well as others not specifically referred to herein, are attained will `be better understood by reference to the following description and to the drawing, in which:

FIG. 1 is a side elevation of a package having flexible walls and a one-way valve structure constituting a presently preferred embodiment of the invention, a portion of one of the outer walls being broken away for purposes of illustration.

FIG. 2 is an enlarged fragmentary longitudinal section on line 2 2 of FIG. 1.

FIG. 3 is a transverse section on line 3 3 of FIG. l showing the inlet end of the liquid passage.

FIG. 4 is a transverse section on line 4 4 of FIG. 1.

FIG. 5 is a transverse section on line 5 5 of FIG. 1 at a position adjoining the exit end of the liquid passage.

FIG. 6 is an enlarged fragmentary longitudinal section on line 6 6 of FIG. 1.

FIG. 7 is a fragmentary side elevation of a package illustrating a variational embodiment of the invention in which the inner walls and the outer walls are respectively integral with each other.

FIG. 8 is a fragmentary longitudinal section on line 8 of FIG. 7.

FIG. 9 is a side elevation of a variational construction of the package, with part of one side wall broken away.

FIG. 10 is an enlarged fragmentary longitudinal section on line N Itl of FIG. 9.

FIG. 11 is an enlarged fragmentary longitudinal section on line 111-11 of FIG. 9.

FIG. 12 is a transverse section on line 1.2 12 of FIG. 9.

FIG. 13 is a fragmentary side elevation of another variational form of package.

FIG. 14 is a fragmentary vertical section similar to FIG. 2, illustrating a modification thereof.

FIG. l5 is a fragmentary vertical section similar to FIG. 2 illustrating a container constructed in a manner similar to the package of FIG. 2.

There will be seen in FIG. l a side elevation of a generally flat, envelope-like package 1t) constructed according to a presently preferred form of the invention. As may be seen in FIG. 2, the package comprises a pair of flexible outer walls 111. and 12 which are made of thin sheet material. The package is shown as being rectangular in outline since this shape is most commonly and easily produced on packaging machines; but it is to be understood that the invention is not necessarily limited to this or to any particular shape of package.

The two opposed, outer walls 11 and 12 are of similar shape and are joined together to form an interior productcontaining space 14 within which is a quantity of a dry powdered product I5. In the fabrication of the package illustrated these two outer walls are originally separate, as they are cut from separate webs, but subsequently they are joined together around the entire periphery of the finished package in order to provide a seal around the entire product space 14. Generally speaking, the invention is independent of the particular means employed to join together these two walls, and consequently the word joined is used in a broad sense. For example, the walls may be integral with each other as in FIGS. 7 and 8 or they may be joined together through an intermediate member, as will be explained. This exemplary package assumes the common practice to make a package from two separate sheets which are joined together by heat seals 16 along the opposite longitudinal margins of the package and by heat seals 18 and 18a at the two opposite transverse margins or ends of the package.

In some types of machines the package is made from a single web which is folded over on itself along a median line to provide the two overlying walls which are thus integral with each other at one edge of the package as in FIGS. 7 and 8. In this latter case the heat sealed areas are located only along the three remaining edges of the package.

In order to form the seals 16, 18 and Ia by the application of heat and pressure, the outer walls are made of sheet material which is heat sealing on the inner face. As typical of the thin flexible materials that may be used for this purpose, there may be mentioned cellulose acetate film, commonly known as Cellophane, coated on the inner face with a layer of polyethylene. The polyethylene is a thermo-plastic material which enables the two walls to be sealed together over an area to which heat and pressure are applied. Other thermo-plastic coatings such as vinyl, or rubber hydrochloride, may be used instead. In addition, the outer walls may have an outer layer of metal foil or other material, as may be desired.

Disposed between the two outer lwalls are two inner walls ZI yand 22, also formed of flexible sheet material which, for reasons which will become evident, is heat sealable on both faces. The two inner walls are rectangular in shape and both extend entirely across one dimension of the package, perferably the shorter dimension or width. The dimension of the inner walls perpendicular thereto is less than the corresponding dimension or length of the outer walls, as is shown clearly in FIGS. 1 and 2, so that the inner edges 21s and 22s of the walls are spaced from one end of the package closed by seal 18a. The inner walls are so located with reference to the outer walls that three edges of the inner walls substantially coincide with edges of the outer walls along three sides of the package. Thus the two inner walls `are sealed between the outer walls throughout the full length of the one end seal I8 and also over portions of the two opposite side lseals 16. This condition illustrates a situation in which the outer walls are joined together through an intermediate element of the package, though not in direct contact with each other.

This latter condition is illustrated in FIG. 2, wherein end seal 18 includes all `four walls. The twoinner walls E? u 21 and 22 are sealed at opposing faces to each other over the area of seal 18. Each of outer walls 11 and 12 is -also sealed to an outer face of the walls 21 and 22, respectively. The seal between the two inner walls at this area closes the end of the liquid passage hereinafter described while attachment of the outer walls to the inner walls is part of the means providing a hermetic seal around the package enclosing the product-containing space 14.

As shown Iparticularly in FIGS. 2 and 6, each of the inner -walls 21 and 22 is joined to the adjoining outer wall 11 and 12, respectively, by a relatively long, narrow heatsealed area 24. Sealed areas 24, extend entirely across the package between side seals 16 and are generally parallel to and spaced from end seal 18. As will become obvious, the two inner walls are not sealed together at 24, although the two heaty seals 24 are preferably opposite each other as shown.

Both inner `walls 21 and 22 are attached to each other by two seal areas 25 and 26 which are preferably narrow, elongated heat seals which are spaced apart from each other and which extend inwardly from or near seal 24. From a functional standpoint, seals 25 and 26 should join seals 24, but for ease of manufacture it is preferred that seals 25 and 26 approach seals 24 and then turn outwardly to join side seals 16. The' short segments of the two side seals between seals 25 or 26 and seals 24 provide continuity between transverse seals 24 andthe two spaced seals 25 and 26. In general, the two seal areas 25 and 26 start from the inner or lower edges 21s and 22s of 4walls 21 and 22 and extend across these walls toward the opposite edge to a position comparatively near the opposite edges thereof. These latter edges are somewhere above or beyond seals 24 depending on the exact construction, but are at the edge of the package in FIG. l'. The space between the two inner walls defined by the two seals 25 and 26 is a filling passage P with its inlet end adjacent the outer edges of the two walls and with its exit end at the inner edges 21s and 22s of these walls. The two seals 25 and 26 taper inwardly in order to give a general funnel-shape to the passage with a larger end being a the inlet end. At the exit end of the passage the two seals 25 and 26 preferably have parallel or substantially parallel, terminal sections at their closest approach to each other.

Both inner walls 21 and 22 ase also connected to one of the outer walls. In the construction illustrated, this outer wall is wall 12. This connection of both inner walls to the one outer wall is most conveniently accomplished by connecting the three `walls together over the seal areas 25 and 26. This permits the connection of the inner walls to the outer wall to be made at the same time and over the same area as the connection of the two Walls to each other.

Thus, the two seal areas 25 and 26 provide a connection of the two inner walls to outer wall 12 at each side of the inner or exit end of the filling passage P formed between the two inner walls. The spacing between the two seals 25 and 26 at the exit end of the passage P is slightly less than the length of material in each of the two inner walls between the points of connection. The result is that there is a small amount of slack or looseness in the two inner Walls at the exit end of the liquid passage that gives to the inner walls an arched conguration when the outer wall 12 is pulled taut. This condition is shown clearly in FIGS. 4 and 5 in somewhat exaggerated and idealized form for purposes of illustration. It will be realized that, because of the limp, flexible nature of the inner walls, they do not assume any given or constant shape at the exit end of the passage. Nevertheless, the effect is to create a configuration of the inner walls that tends to hold the two walls in mutual contact.

This construction produces a o-ne-way valve construction that is effective in preventing the contents from entering the liquid passage from the interior space of the package during mixing while at the same time permitting liquid to be introduced into the product space through the unsealed passage P. Since both inner Walls are attached to one outer wall, there is no tendency for the inner walls to be separated as a result of the outer walls being spread apart by internal pressure. Furthermore, the slack in the two inner walls just described forms a loose fold in the two walls tending to keep the two walls always in contact with each other, thus resisting entry of material from the product space into the liquid passage Without at any time resisting flow of liquid through the passage when introduced into the inlet end.

Not essential to the proper operation of the package but convenient to the user, are the two seals 27 and 28. These seals extend from seals 25 and 26, respectively, to the side seals 16 and are located at or closely adjacent to thelower edges 21s and 22s of the inner walls. Seals 27 and 28 seal the inner walls together and also to outer wall 12 for the purpose of preventing the contents of the package from working up into the confined spaces within the package between inner wall 22 and the adjoining outer wall 12. In the absence of barrier seals 27 and 28, a small amount of the contents can become trapped during mixing in these parts of the package. This is undesirable since it interferes with proper mixing of the contents and also results in a certain amount of unnecessary waste.

The completed package with its contents hermetically sealed in it appears as shown in FIG. 1. In order to use the package the end seal 18 is removed by cutting all -four walls transversely across the package substantially along the line 3--3 between seal areas 18 and 24. This results in free access to the inlet end of the filling passage P as shown in FIG. 3. -The passage can be opened up by spreading apart the inner walls to give a funnel-li-ke shape to the passage, and a suitable amount of any desired liquid can then be poured easily into the package, the liquid falling down through the passage P between inner walls 21 and 22. The liquid flows easily by gravity as its weight forces the inner walls apart, providing easy entry of the liquid into the product-containing space 14.

The liquid and the dry product are now mixed together by kneading or llexing the walls of the package to provide suitable mixing or agitation of the contents -of the package. After a suitable mixture of the contents is achieved, the semi-fluid contents are now squeezed out of the bag through an opening created expressly for this purpose. This can easily be done by cutting off a c-orner of the package along the line 30, thus creating-a second opening of easily controlled size. through which the contents can be discharged at a fully controlled rate.

Mixing action can be carried out easily because of the very flexible nature of the thin, pliable walls -of the package. It will be seen that substantially the entire volume of the package interior between transverse seal area 24 and end seal 18a is available for the mixing operation. The inner walls, because of their connection to outer wall 12, both lie against the one outer wall and the normal pressures exerted by the contents on these walls during the mixing 1operation tend to press the inner walls against each other. Also, because the two inner walls are connected to only one outer wall, the relative motion of the two outer walls caused by' kneading during mixing exerts no force -on the inner walls tending to separate them to allow escape of the product. The result is that the inner walls remain in contact with each other during the mixing operation and effectively close the filling passage to the escape -of the contents. i

For purposes of disclosure, the package has been described as being originally filled with a dry, iluent product 15 to which a liquid is to be added. This is equally within the scope of the invention to lill the package initially with a liquid or semiliquid material or to add a fluent powder or dry substance through passage P.

The package described can `be made from four separate webs, the packages being severed from the ends of the webs as they are completed. One method is to feed into the machine two webs in parallel, opposed relation to provide the two inner walls. The outer walls are then fed in one on each side of the two inner walls, so that the outer walls are a parallel, opposed relation to each other. Assuming the webs moved from right to left in FIG. l, continuous heat seals are formed at 24. Each seal 24 joins one inner wall to the adjoining or overlying outer wall. The seal 24 is at an area relatively adjacent one edge of the inner web and extend in the direction of web travel.

Next the walls are joined by heat seal 1S along one margin. This stabilizes the positions of the webs relative to each other, preparatory to placing the seals 25 and 26 forming the filling passage. These latter seals are preferably `formed by a single die that places simultaneously the seal 25 of one package and seal 26 of the adjoining package. Alternatively, a single die may place both seals on a single package at one time. The seals 27 and 28 are placed by the same die; and, as mentioned above, not only are the two inner walls sealed to each other but both are connected to one outer wall. This involves removing the other outer wall from the action of the sealing die, as by folding the wall back enough to allow the die to operate inside that wall and contact the inner wall thereby exposed.

To insure that there is excess material in the inner walls between the parallel terminal sections of seals 25 and 26, a forming shoe is inserted between the inner wall and the outer wall to which it is sealed, in the example walls 22 and 12. The shoe is of a size to produce the desired curved or arched configuration of the inner walls. After placing seals 25 and 26, the shoe is retracted allowing the webs to advance.

Next the side seals are placed, joining the outer walls together in a manner to partially enclose the productcontaining space but leaving one end of the package open. The product is introduced through this open end, after which final seal 18a is placed to hermetically seal the package.

A modified form of the invention is shown in FIGS. 7 and 8 that is constructed in most respects in the same way as described above. It differs in that the two outer walls are made from a piece cut from a single web folded along a median axis to bring the two walls into opposed relation. As a consequence walls 11a and 12a are integral at the fold 31. End seal 18 may be placed as in FIG. 1 or it may be omitted as shown in FIG. 8 since the integral character of the walls closes the package. The inner walls 21a and 22a are likewise made from a single sheet or web folded at 32 to bring the two walls into opposing positions. Since the two inner Walls are integral with each other at their outer edges, it is not necessary to seal them together, as at 1S, as a means for closing the upper end of the filling passage P.

As before, the' seals 25a and 26a join the inner walls 21a and 22a together and to outer wall 12a. The seals 25a and 26a deiine the filling passage and flare outwardly at their outer ends to merge with the side seals 16. The segments of the side seals 16 between the seals 25a or 26a and seal 24 serve to define in part the complete iiuid passage.

As in the first described form, the filled package is opened by removing the end of the package including the two folds 31 and 32, thus destroying the continuity of the inner and outer walls respectively. This is done typically by cutting across the package within the area of seal 24 or between seal 24 and the near end. This breaks the hermetic seal around the contents by removing completely the end sealed area 18 and opens the passage P to admit water or other liquid at the wide end and conduct it into the product space 14.

From the above description, another variational form of the invention will be obvious without detailed description. The package may be constructed without extending the inner walls into the end sealed area 18. In other words, the inner walls 21 and 22 may have their upper or outer edges positioned just beyond the sealed area 24, as shown in FIG. 14. However, the construction shown in FIG. 2 is favored as it makes for casier and surer handling of the webs in a high speed machine.

The embodiments of the invention thus far described have been designed for ease of manufacturing from continuous web stock. Each package as completed is severed by a single cut from the following webs. Web travel is transverse to the longer dimension, that is, from right to left, or vice versa, in FIG. l; and consequently the inner and outer walls are equal in extent in this direction, or substantially so. It is obvious however, that the portions of walls 21 and 22 laterally bey-ond seals 25 and 26 have no functional utility in Arespect to the filling passage and that these portions may be omitted. A package 10b of this type is shown in FIGS. 9-12.

Referring to FIGS. 9-12 it will be seen that outer walls 11b and 12b are duplicates of walls 11 and 12 and are similarly joined by marginal heat sealed areas 16, 18 and 18a. Inner walls 21b and 22b are now shaped to conform more or less closely to the outline of the funnelshaped filling passage P to be provided by and 'between these two inner walls. As already described, the sealed areas 25h and 2Gb join the inner walls together and the walls are also attached both to one outer wall, wall 12b, by seal areas assumed to coincide with areas 25]: and 26h, though they may not, depending on the manner of making the package. Seals 25h and 26h are now along opposite margins of walls 21h and 22b and the latter do not extend into side seals A16.

Each of the inner walls 2lb and 22h is attached to the adjoining outer walls 11b and 12b respectively over the seal area 24b. This seal extends across the full width of the inner walls and is preferably extended at 34 at each end to meet seals 16. It will be realized that these extensions 34 are beyond the inner walls and so the seal here includes only the outer Walls. To this extent these extensions 34- may also be viewed as enlargements or extensions of seals 16 or 18. Their purpose is lto prevent escape of product duning the rnixring operation and yafter the end of the package has been removed to open the passage P for filling.

The inner walls 2lb and 22b preferably, though not necessarily, extend beyond seal 24b .and into the area of seal 18 where the walls are Isealed to each other and to the adjoining outer walls as shown in FIG. l0. Because the inner walls are narrower than the outer walls, at the end sections of seal 18 only the outer walls are included and they are sealed to each other as shown in FIG. 11. These corners where seals 16 and 18 join have no function insealing or enclosing the contents tand the package can be further modified as in FIG. 13 by omitting the portion of outer walls 11b and 12b beyond the transverse seal 24h and merely sealing together the ends of the pas sage-forming walls Ias at 35.

The foregoing description has related to a filled packlage as an example illustrating most fully the advantages of the present invention. From that description it will be self-evident that the invention has utili-ty as an inexpensive, disposable mixing container. As such it will be made and merchandised without any product in it and the two or more products to be mixed will be -added in turn by the user. A mixing container of this character is produced by the very simple change of omitting from the package of FIG. 1 all, Ior at least a large part, of end seal 18 between the two side seals 16. The resulting container may be compared with the package in the state produced by cutting oif the end portion of the package yalong a line between seals 24 Iand 1S, in the vicinity of section line 3 3. Another sytle of container is obviously produced by omitting the seal 35 for the inner walls in FIG. 13.

Investigation of various designs leading to the present invention has indicated that any uncontrolled wrinkle or fold formed in one wall of the passage during the kneading operation opens the valve'. Hence, all forms of the present invention are designed to :place a controlled curvature in 'both walls of the filling passage at the outlet end. The curved or .arched configuration holds the walls in mutual contact, even during the kneadin-g operation. Fastening 'both walls of the passage to one outer wall alone eliminates any relative movement of the passage walls cause-d by relative movement of the outer walls.

It will be obvious from the variety of modifications of the invention disclosed above that vari-ous other changes and modifications of the package and container of the present inve-ntion may occur to persons skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is to be un-derstood the .above description is considered to be illustrative of, rather than limitative upon the invention.

We claim:

1. A package containing la product t 'be mixed with .a substance to Ebe added, comprising:

-a pair of opposed, flexible outer walls enclosing anl interior product-receiving space;

a quantity of product in said space;

and a pair of opposed, fiexible inner Walls disp-osed between the outer walls :and joined to each other and to only one outer wall at two spaced areas that extend inwardly from one edge of the outer walls to define opposite boundaries of a filling passage between said inner walls and communicating at its inner end with said space;

said inner walls being attached respectively to one adjoining outer wall at said one edge thereof,

and said inner walls having between said spaced attachment areas and adjacent the inner end of the passage an arched configuration that holds the two walls of the passage in mutual contact independently of the presence of .a product in said vsp-ace t-o prevent escape of the product through said passage.

2. A package as in claim 1 in which the two inner walls are joined to each other to close the inlet end of the passage.

3. A package as in claim 1 in which the filling passage is wider at the outer end than at the inlet end and is of substantially uniform width for a portion of its length adjoining the .inner end.

4. A package as in claim 1 in which the two inner walls are joined to each other, to close lthe filling passage at the outer end thereof, at one end of the package .at .a first location generally parallel to :and spaced from .the location of said attachment of the inner Walls to the respective adjoining outer walls, whereby a cut between the two locations opens the filling passage to permit a substance to be placed therein.

5. A package 4as .in claim 1 in which the ou-ter walls are heat sealable on the inner faces and the inner walls are heat sealable on both faces.

6. A package as in claim 1 in which the outer walls a-re sealed to the inner Walls andthe inner walls are sealed to each other over a marginal are-a closing both one side of the product-receiving space and one end of the filling passage.

7. A package as in claim 1 in which the inner walls are coextensive in one dimension with t-he outer walls 'but shorter than the outer Walls in the dimension perpendicular to said one dimension.

8. A package as in claim 1 which also includes heat scale-d areas extending laterally from the first mentioned spaced apart areas to opposite margins of the package along an edge of the inner `walls and attaching both inner walls to one outer Wall. l

9. A package as in claim. 1 in which the inner and outer walls are .heat sealed together over marginal areas adjoining opposite edges of the package and the first mentioned spaced 4apart sealed areas and the second mentioned sealed areas terminate in the marginal sealed are-as at opposite edges of the package.

10. A mixing container adapted to receive substances to be mixed therein, comprising:

a pair of opposed, fiexible outer Walls enclosing an interior space;

Vand -a pair of opposed, flexible inn-er walls disposed between the outer walls and joined to each other and to only one louter w-all at two spaced areas that extend inwardly from .one edge of the outer walls to define opposite `boundaries of a filling passage between said inner walls -and communicating at its inner end with ysaid space;

said inner walls being attached respectively to one adjoining outer wall at said one edge thereof,

land said inner walls having between said spaced attachment areas and adjacent the inner end of the passage an arched configuration that holds the two walls of the passage in mutual contact independently of the .presence of la product in said space to prevent escape of the product through said pass-age.

11. A container as in claim 10 in which said two spaced apart areas over ywhich the two inner walls are sealed to each other extend substantially parallel to eac-h other adjoining the inner end of the filling passage.

12. A container as in claim 10 in which the outer walls are heat sealable on the inner faces and the inner walls are heat sealable on both faces.

13. A container as in claim. 10 in which the inner walls are coextensive in one dimens-ion Wi-th the outer walls but shorter than the outer walls in the dimension perpendicular to said one dimension.

14. A container as in claim 10 in which the inner and outer walls lare heat sealed together over marginal areas adjoining opposite edges of the container and the first mentioned spaced apart sealed areas and the second mentioned sealed areas at which the inner walls are attached to the respective outer walls, terminate in the marginal areas at opposite edges ofthe container.

15. A container adapted to receive la fluid to be mixed with a product the-rein, comprising:

outer walls of a thin liexible material enclosing an interior space and having an opening therein; and

a selfclosing valve structure at said opening and i-nsid-e the outer walls, said valve comprising :a -pair of opposed flexible walls defining a tubular passage extending inwardly from said opening and communicating with lthe interior space,

said inner walls being attached to one outer wall land free of the other wall for substantially the length of the passage, and said inner walls being sufficiently flexible that they .are normally -in contact w-i-th each other for substantially the length of the .passage yet can separate under the weight of fiuid in the passage to allow a fluid to pass into the interior space.

16. A container as in claim 15 in which the inner Walls are normally curved transversely of the 4passage to hold the walls of the passage in mutual contact to prevent escape of substances from said Iinterior space.

17. A package containing a product to be mixed with a substance to be added, comprising:

a pair of opposed, flexible outer walls enclosing an interior product-receiving space;

a quantity of product in said space;

and a pair of opposed, flexible inner walls disposed between the outer walls .and joined to each other and -to only one outer wall -at two spaced areas that extend inwardly from one edge of the outer Walls to define opposite boundaries of a filling passage between said inne-r walls communicating with said space;

said inne-r Walls being attached respectively to one adjoining outer wall at said one edge thereof,

and sai-d inner walls being joined to each other to close the .inlet en-d of the passage.

18. A package as in claim 17 in which the two inner 2,879,635 3/ 1959 Brock 53-28 walls are formed from a single sheet folded on itself, the 3,009,498 11/ 1961 Fohr 150-9 fold closing the inlet end of the passage. 3,051,209 8/ 1962 Gonz-allez 150-9 3,150,473 9/ 1964 Lemelson 5328 References Cited by the Examiner 5 3,181,439 5/1965 Flax 150-9 X UNITED STATES PATENTS 2,800,269 7/1957 Smith u 2129 6`2 5 THERON E- COND'ON,1"'"11110' Examlner- 2,804,257 s/1957 Hacker et a1 229-4525 J- M- CASKIE, ASSISMM Exammef- 2,828,858 4/1958 Tooke 206-47 

1. A PACKAGE CONTAINING A PRODUCT TO BE MIXED WITH A SUBSTANCE TO BE ADDED, COMPRISING: A PAIR OF OPPOSED, FLEXIBLE OUTER WALLS ENCLOSING AN INTERIOR PRODUCT-RECEIVING SPACE; A QUANTITY OF PRODUCT IN SAID SPACE; AND A PAIR OF OPPOSED, FLEXIBLE INNER WALLS DISPOSED BETWEEN THE OUTER WALLS AND JOINED TO EACH OTHER AND TO ONLY ONE OUTER EALL AT TWO SPACED AREAS THAT EXTEND INWARDLY FROM ONE EDGE OF THE OUTER WALLS TO DEFINE OPPOSITE BOUNDARIES OF A FILLING PASSAGE BETWEEN SAID INNER WALLS AND COMMUNICATING AT ITS INNER END WITH SAID SPACE; SAID INNER WALL BEING ATTACHED RESPECTIVELY TO ONE ADJOINING OUTER WALL AT SAID ONE EDGE THEREOF, AND SAID INNER WALLS HAVING BETWEEN SAID SPACED ATTACHMENT AREAS AND ADJACENT THE INNER END OF THE PASSAGE AN ARCHED CONFIGURATION THAT HOLDS THE TWO WALLS OF THE PASSAGE IN MUTUAL CONTACT INDEPENDENTLY OF THE PRESENCE OF A PRODUCT IN SAID SPACE TO PREVENT ESCAPE OF THE PRODUCT THROUGH SAID PASSAGE. 